PSI - Issue 73

Pavel Dobeš et al. / Procedia Structural Integrity 73 (2025) 1–8 Author name / Structural Integrity Procedia 00 (2025) 000–000

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A01. The numerical model is in a good agreement with the experimental measurements. This is confirmed by the statistical indicators, where the coefficient of determination reaches R 2 ≈ 0.99, the mean absolute error (MAE) is 0.65 kN, and the root mean square error (RMSE) is 0.74 kN. These values demonstrate that the numerical predictions closely follow the experimental response.

Fig. 8. Comparison of load-deformation diagrams for the wall panel with horizontally oriented OSB boards A01 (Lokaj et al. 2023).

4. Discussion The experimental findings clearly demonstrate that wall panels with unglued, horizontally oriented OSB boards provide the least favorable structural performance in terms of both horizontal stiffness and load-bearing capacity. Compared to glued joints, unglued configurations showed approximately four times lower stiffness and significantly lower racking resistance. This aligns with the expectation that lack of continuity in shear flow leads to reduced structural efficiency. Glued tongue-and-groove joints substantially improve the performance, resulting in stiffness even higher than that of standard vertically sheathed panels. These results suggest that, when properly glued, horizontal OSB boards form a rigid diaphragm capable of efficiently transferring loads. While this configuration is not explicitly addressed in current European standards such as Eurocode 5, the findings indicate its suitability for structural applications, provided its reliability is confirmed through testing. The numerical simulations reinforced the experimental results, accurately capturing both deformation patterns and stress distributions. The models revealed consistent agreement with measured data and proved useful in predicting panel behavior beyond the physical tests. They also allowed for better understanding of internal force redistribution, which is crucial in the design of reliable timber structures. Although some construction practices still employ unglued horizontal OSB sheathing for its simplicity, author’s findings highlight the significant structural risks associated with such methods. Without a properly bonded joint system, the wall panels cannot maintain adequate stiffness and fail to meet expected performance criteria. Therefore, this approach is not recommended for load-bearing walls in timber-frame construction. 5. Conclusion This research examined the horizontal stiffness and load-bearing behavior of timber wall panels with various OSB sheathing configurations in lightweight frame systems. The study confirmed that glued horizontal tongue-and-groove joints significantly improve structural performance and can outperform vertically oriented sheathing in terms of stiffness. Experimental tests were supported by detailed numerical models, which proved valuable for understanding stress distribution and predicting deformation under load. These models provide a practical supplement to physical testing and can help evaluate more complex design scenarios, such as panels with openings or varying boundary conditions.